Large concrete/grass/base materials for map editing

I've started working on some map editing, but am finding it difficult to locate materials with which to create an even base to build on. I'd like to find some large concrete, grass, or similar objects to work with. Can anybody recommend particular models? I tried looking in a bunch of RPFs and using the codewalker map viewer tool, but haven't found anything useful yet.

Hmm. @DarthPungz I wasn't able to find any good concrete chunks at either of those places, they all seem to be part of the map, with lots of stuff all together on giant tiled "objects". @Shaezbreizh that's a good idea - I already have an add-on DLC with this mod so it would be easy enough to throw a retextured prop in there. Just annoying there isn't something already pre-built to use!

@PNWParksFan we've build an addonprops mod to be spawned with map editor or menyoo if you need. Not a lot of prop in current version but next one is around 800 props
Else if that for moddeling I'm sorry but I only allow co-author to reuse the prop ( but I accept anyone in co-author till he share his object with everyone for object spawner map ).